The patch titled
Subject: mm: replace vma->vm_flags indirect modification in ksm_madvise
has been added to the -mm mm-unstable branch. Its filename is
mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: mm: replace vma->vm_flags indirect modification in ksm_madvise
Date: Wed, 25 Jan 2023 15:35:52 -0800
Replace indirect modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.
Link: https://lkml.kernel.org/r/20230125233554.153109-6-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c~mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise
+++ a/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -393,6 +393,7 @@ static int kvmppc_memslot_page_merge(str
{
unsigned long gfn = memslot->base_gfn;
unsigned long end, start = gfn_to_hva(kvm, gfn);
+ unsigned long vm_flags;
int ret = 0;
struct vm_area_struct *vma;
int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE;
@@ -409,12 +410,14 @@ static int kvmppc_memslot_page_merge(str
ret = H_STATE;
break;
}
+ vm_flags = vma->vm_flags;
ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
- merge_flag, &vma->vm_flags);
+ merge_flag, &vm_flags);
if (ret) {
ret = H_STATE;
break;
}
+ reset_vm_flags(vma, vm_flags);
start = vma->vm_end;
} while (end > vma->vm_end);
--- a/arch/s390/mm/gmap.c~mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise
+++ a/arch/s390/mm/gmap.c
@@ -2587,14 +2587,17 @@ int gmap_mark_unmergeable(void)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
+ unsigned long vm_flags;
int ret;
VMA_ITERATOR(vmi, mm, 0);
for_each_vma(vmi, vma) {
+ vm_flags = vma->vm_flags;
ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
- MADV_UNMERGEABLE, &vma->vm_flags);
+ MADV_UNMERGEABLE, &vm_flags);
if (ret)
return ret;
+ reset_vm_flags(vma, vm_flags);
}
mm->def_flags &= ~VM_MERGEABLE;
return 0;
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
kernel-fork-convert-vma-assignment-to-a-memcpy.patch
mm-introduce-vma-vm_flags-wrapper-functions.patch
mm-replace-vm_locked_clear_mask-with-vm_locked_mask.patch
mm-replace-vma-vm_flags-direct-modifications-with-modifier-calls.patch
mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise.patch
mm-introduce-mod_vm_flags_nolock-and-use-it-in-untrack_pfn.patch
mm-export-dump_mm.patch
